Grease your muffin pan (whatever size) or use the silicone cups. I grease my silicone muffin cups with Crisco or lard. In a medium bowl, stir together brown sugar, flour and pecans. In a separate bowl, beat the butter and eggs together until smooth. Stir into the dry ingredients just until combined. Spoon the batter into the prepared muffin cups. Cups should be about 2/3 full. Bake for 20 to 25 minutes. Cool on wire racks when done. Option: when you take them out of the oven, place a slice of butter on top and eat warm. You may also use walnuts instead of pecans.